package etc.ali.q4; import java.util.ArrayList; import java.util.Date; import java.util.List; public class Main { private static List list1 = new ArrayList<>(); private static List list2 = new ArrayList<>(); private static List list3 = new ArrayList<>(); static { Info1 info1 = new Info1(); info1.setUserId(1L); info1.setGoodsId(1L); info1.setBuyTime(new Date()); info1.setCost(20.00); list1.add(info1); Info2 info2 = new Info2(); info2.setUserId(1L); info2.setGoodsId(1L); info2.setAddress("测试"); list2.add(info2); } public void merge(){ for (int i = 0; i < list1.size(); i++) { Long userId = list1.get(i).getUserId(); Long goodsId = list1.get(i).getGoodsId(); for (int j = 0; j < list2.size(); j++) { if (userId.equals(list2.get(j).getUserId()) && goodsId.equals(list2.get(j).getGoodsId())) { Info3 info3 = new Info3(list1.get(i),list2.get(j)); list3.add(info3); } } } } public static void main(String[] args) { new Main().merge(); for (int i = 0;i